Portable communication devices, such as cellular telephones generally use a vertically mounted antenna for the transmission and reception of radio frequency signals. Several types of antennas, such as half-wave and quarter-wave are presently used with such devices. A problem with present antennas is the capacitive and inductive coupling to the body of the user. This body coupling degrades the performance of the antenna, and ultimately the communication device, due to reflection, diffraction and dissipation by the Joule effect of the RF (Radio Frequency) energy by the body of the user. A very common antenna is the quarter-wave whip and physically shorter quarter-wave antenna which is popular due to its size. The radiation patterns of quarter-wave antennas tend to have a deep null behind the head of the person holding the radio. This null can not be accurately characterized as the holding position of the radio changes from one user to the next. Indeed, the closer the radio is held to the body the deeper this null. Since some radio applications demand that the user hold the radio to their ear, e.g. cellular phones, the designer is forced to compromise the performance of the radio in order to achieve the device's intended use.
One solution to this problem is to locate the antenna remotely. In addition to cost disadvantages, this solution is bulky and not user friendly. Other solutions involve the use reflectors to render the antenna directional. The problem with using reflectors is that the antenna grows in size and may not be well suited for portable applications.
It can be seen that an antenna is desired that overcomes the performance problems of the prior art without sacrificing the convenience